1. Field of the Invention
The present invention is related to an inflator, and more particularly to an inflator that can provide a compressed air supply whether by moving a piston downward or upward.
2. Description of Related Art
An inflator, which is used for inflating a bicycle tire, accomplishes the inflation only by pushing a rod of a piston downward. When the rod of the piston is pulled upward, the inflator cannot inflate the tire.
Now a dual-direction inflator which can inflate a tire whether by pushing a piston downward or by pulling it upward is invented.
Referring to FIGS. 9 and 10, the conventional dual-direction inflator has a tube (70) and a cover (80) mounted on a top of the tube (70). An inner tube (72) is longitudinally and eccentrically provided in the tube (70) and a first non-return valve (74), by which air in the inner tube (72) can flow out, is mounted on a top end of the inner tube (72). An orifice (76) is defined at a bottom end of the inner tube (72). By the orifice (76), the inner tube (72) is communicated with the tube (70). The cover (80) has an outlet (82) defined therethrough and a first air chamber (84) is defined in a bottom portion of the cover (80) and is communicated with the outlet (82). An aperture (86) is defined through a bottom surface of the cover (80) and aligned with the inner tube (72). The inner tube (72) is communicated with the air chamber (84) via the aperture (86), then air in the inner tube (72) can flow through the first non-return valve (74), the aperture (86) and the first air chamber (84) and out from the outlet (82). A second non-return valve (88), by which air in the tube (70) can flow in the air chamber (84), is provided at a diametrically opposite side of the aperture (86).
A rod (90) is inserted through the center of the cover (80) and has a piston (92) formed at a bottom end of thereof and received in the tube (10). The piston (92) has a passage (93) defined therethrough and the inner tube (72) is inserted through the passage (93). A second air chamber (94) is defined in the piston (92) and two third non-return valves (95, 96), by which air in the second air chamber (94) can flow in the tube (70), are respectively formed on a top and a bottom of the second air chamber (94). A handle (98) is provided at a top end of the rod (90). An inlet (99) is defined in the handle (98) and communicated with the second air chamber (94) through the rod (90).
When a user pulls the handle (98) to move the piston (92) upward, air above the piston (92) in the tube (70) flows in the first air chamber (84) through the second non-return valve (88) and then flows out through the outlet (82) for inflating a tire etc. At the same time, external air flows through the inlet (99) and the rod (90) into the second air chamber (94), and then flows through the lower third non-return valve (96) in the tube (70) beneath the piston (92).
When the user pushes the handle (98) to move the piston (92) downward, air beneath the piston (92) in the tube (70) flows sequentially through the orifice (76) in the inner tube (72), the first non-return valve (74), and the first air chamber (84), and then flows out through the outlet (99) for inflating a tire etc. At the same time, external air flows through the inlet (99) and the rod (90) into the second air chamber (94), and then flows through the upper third non-return valve (95) in the tube (70) above the piston (92).
By the rod (90) being pulled and pushed repeatedly, the inflator can quickly inflate a tire.
However, as the inner tube (72) must be inserted through the piston (92), there are two airproof points, one of which is between the tube (70) and the piston (92), the other of which is between the inner tube (72) and the passage (93). Those points make it disadvantageous to manufacture and maintain the inflator. Moreover, the handle (98) is securely mounted on the rod (90) and the piston (92) also cannot be turned in the tube (70), so that the handle (98) cannot be turned about the tube (70). If a user carelessly turns the handle (70), the piston (92) or the inner tube (72) may be destroyed. A further problem is that using the dual-direction inflator requires more energy to be input by a user and such effort may be beyond what a child etc can provide. Thus, the limitation of being usable only as a dual-direction inflator is inconvenient and may render the inflator useless.
Therefore, the invention provides an improved dual-direction inflator to mitigate and/or obviate the aforementioned problems.
The main objective of the invention is to provide an inflator of which a handle can be freely turned about a tube.
Another objective of the invention is to provide an inflator which can be configured to expel compressed air when a piston is either moved downward or downward and upward.
Other objects, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.